CVE-2026-89743: Linux kernel · misc: nsm: bound the device-reported response length
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.7 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that bounds the device-reported response length to the size of the response buffer, preventing out-of-bounds reads. Users should apply the official Linux kernel updates that include this patch. Since this is a kernel-level vulnerability, upgrading to patched kernel versions is the recommended remediation. No additional mitigations are specified or required for conforming devices.
Description
A vulnerability in the Linux kernel's NSM device handling allows an out-of-bounds read due to improper bounding of the device-reported response length in nsm_sendrecv_msg_locked(). This can lead to disclosure of adjacent kernel heap memory. The issue affects specific Linux kernel versions and has been resolved by clamping the response length to the buffer size.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89743 (opens in a new tab)
- git.kernel.org/stable/c/29e634a18957acda11383a15ab98a91c4ae9e294 (opens in a new tab)
- git.kernel.org/stable/c/2aa0fb9c96f894a9c179a48e7522ea6705800adf (opens in a new tab)
- git.kernel.org/stable/c/339f19b9a6171289b0e797deb8bda80b9a1fcc30 (opens in a new tab)
- git.kernel.org/stable/c/808e530654a5354e6df78863a5d61e4d44e67235 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89743 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89743 (opens in a new tab)
- git.kernel.org/linus/808e530654a5354e6df78863a5d61e4d44e67235 (opens in a new tab)